P3436Cylinder 5 Deactivation/Intake Valve Control Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P3436 is the short-to-power code for the cylinder 5 deactivation valve. Publicly it is documented by GM for the L84 V8 (2019), where Dynamic Fuel Management uses a dedicated valve lifter oil solenoid for each of the eight cylinders. The engine computer checks the line while its low-side driver is on; an impedance below 0.5 ohm toward supply voltage counts as a fault, confirmed by 20 of 25 samples at 250 ms, with at least 11 V and 425 rpm. As a Type B code it lights the lamp after two consecutive trips. Because the solenoid then cannot be switched in a controlled way, cylinder 5 is excluded from deactivation. Siblings: P3433 open, P3435 short to ground, P3434 function.
- What you may notice
- Check engine lamp after two trips
- Dynamic Fuel Management disabled
- Likely causes
- LikelyControl wire touching a voltage supply
- PossibleShorted coil in the cylinder 5 solenoid
- RareEngine control module output stage defect
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.